This manual is designed to introduce extension workers to needs assessment theory and techniques in an applied context and to serve as a tool for planning and implementing county-level assessments of youths' needs for extension education (including 4-H programs). First, the following steps in the program planning process are explained: identify issues, determine needs, set goals and objectives, assess resources, form a plan, implement the plan, and evaluate results. Selected aspects of the needs assessment process are examined (including critical questions for needs assessments, examples of target groups and informants, reasons for conducting/not conducting needs assessments, and strategies). The following office techniques for conducting needs assessments are discussed and illustrated with sample forms/instruments: needs sheet/wall chart, resource inventories, review of office records, futures wheel, and reflective listening. The roles of the following data/data collection instruments in assessing needs are described: social indicators, written surveys, phone surveys, the nominal group process, county forums, focus group interviews, and brainstorming. Concluding the manual are a summary of Pennsylvania county youth needs assessments conducted during 1987-91 and lists of the following: other needs assessment techniques, common misuses of the needs assessment techniques described, and benefits of county advisory committees. (Contains 21 references.) (MN)